JPH06186091A - Device for monitoring premise of factory or like - Google Patents

Abstract

PURPOSE:To enable integral monitoring of various kinds of devices by installing in a place for monitoring an optical fiber connected to a pulse beam transmitter- receiver, and installing optical communications transmitter-receivers in a plurality of appropriately separate points on the optical fiber. CONSTITUTION:Should a pit 6 be inundated or a fire occur at a point 15 or a low-temperature fluid make contact with a point 16, scattering of transmitted light occurs at those portions of an optical fiber 5. In response to a signal from a transmitter-receiver 2, a processor 3 determines the position of the scattering as the distance along the optical fiber 5, from the delay time of backscattered light reflected. A position in premises which corresponds to the point where the backscattered light has occurred is specified in accordance with the distance and data on the installation of the optical fiber. The point is displayed on a display device 4, together with the map of the corresponding place in premises, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring device in a premises such as a plant or factory.

[0002]

2. Description of the Related Art A device for measuring the temperature of each part of an optical fiber by the principle of a radar is known as an optical fiber distributed temperature measuring device by utilizing the fact that the optical characteristic of the optical fiber is changed by the change of temperature. There is. That is, this device uses the phenomenon in which the intensity of the backscattered light of the laser pulse light propagating in the optical fiber changes depending on the temperature of the optical fiber at each location, and the optical fiber itself is used as a sensor. The ambient temperature is measured in a distributed manner.

There is known a device that uses such a distributed temperature measuring device to monitor the temperature of each part of the device to be monitored. For example, the one disclosed in Japanese Patent Application Laid-Open No. 4-72389 uses an LNG vaporizer as a monitoring target device.

[0004]

SUMMARY OF THE INVENTION The above-mentioned device is intended to monitor the temperature of the device as a single target, and is not used comprehensively for monitoring equipment such as various devices on the premises of a factory or the like. Absent. The present invention aims to solve such problems.

[0005]

In order to solve the above-mentioned problems, according to the present invention, an optical fiber connected to a transmission / reception device for pulsed light is installed over a monitoring target location in a premises such as a factory, and We propose a monitoring device such as a factory in which a transmitting / receiving device for optical communication is installed at least at two points appropriately separated from each other through an optical fiber.

[0006]

The change in the optical characteristics of the optical fiber is caused not only by the change of the temperature but also by the strain due to the external force or the change of the material due to the absorption of moisture. Therefore, it is possible to monitor the external force and moisture as well as the temperature of the monitoring target corresponding to such a change.

Therefore, by installing an optical fiber as a sensor connected to a pulse light transmitting / receiving device over a desired monitoring target location in a premises such as a factory, comprehensive monitoring of equipment and the like is performed. be able to.

On the other hand, a communication line is required between the premises and another place or between the premises for communication of telephone calls and transmission of various kinds of data. As the communication line, an optical fiber as the above-mentioned sensor should be used. You can That is, if a transceiver for optical communication is installed at at least two points on the optical fiber at appropriate distances via a multiplexer, the transceiver can communicate with each other.

[0009]

Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1 is a system diagram showing the overall configuration of the apparatus of the present invention, and the right side of the two-dot chain line in the figure shows the premises of a factory or the like.

Reference numeral 1 is a monitoring device main body, and the monitoring device main body 1 controls the pulsed light transmitting / receiving device 2 and the transmitting / receiving device 2, and processes signals from the transmitting / receiving device 2 to perform predetermined monitoring as described later. It is composed of a processing device 3 and a display device 4 which operate.

Reference numeral 5 denotes an optical fiber connected to the transmitter / receiver 2, and the optical fiber 5 is installed over the monitoring target points on the premises. Explaining these installation locations, first, reference numeral 6 is a pit on the premises, and the optical fiber 5 is installed at a predetermined height in the pit 6. Reference numerals 7 and 8 denote valves, and the optical fiber 5 is installed at a position where strain such as tensile force is applied to the optical fiber 5 during opening / closing operation of the valves 7 and 8. Reference numeral 9 is piping, and the optical fiber 5
Is stretched by a support member 10 between two points of the pipe 9 which are separated from each other. On the other hand, reference numerals 11 and 12 are transmitters / receivers for optical communication, and these transmitters / receivers 11 and 12 are formed at two points of the optical fiber 5 via multiplexers 13 and 14, respectively.

In the above configuration, the transmitter / receiver 2
For example, when a laser pulsed light with a wavelength of 1.5 μm is transmitted to the optical fiber 5, the pulsed light propagates through the optical fiber 5 due to a temperature difference from an adjacent point, a point distorted by an external force, or absorption of moisture. A part of the material is deteriorated and scattered, and the light is returned to the transmitter / receiver 2 as backscattered light.

For example, if the inside of the pit 6 is submerged and the optical fiber 5 is submerged, moisture is adsorbed to the optical fiber 5 and the material is deteriorated, and the transmitted light is scattered at this portion. When a fire occurs at the point indicated by reference numeral 15 and the optical fiber 5 is locally heated, the transmitted light is scattered at this portion. On the contrary, when the low temperature fluid leaks from the pipes and the low temperature fluid locally cools the optical fiber 5 at the point indicated by reference numeral 16, the transmitted light is scattered also in this portion. Further, in the bulbs 7 and 8, the transmitted light is scattered at this portion due to the strain corresponding to the opening degree thereof. In addition, if the distance between the support members 10 is expanded at some portions installed at the nine pipes due to some cause, a tensile force is applied to the optical fiber 5 at this portion to cause distortion, so that scattering of transmitted light occurs at this portion. .

In the signal from the transmitter / receiver 2, the processor 3 can obtain the position of the scattering occurrence point as the distance along the optical fiber 5 from the delay time of the reflected backscattered light. It is possible to specify the position on the premises corresponding to the generation point of the backscattered light from the installation data of. Also, from the intensity of the backscattered light that has been reflected,
The degree of the above distortion and the like can be obtained. Then, the above-mentioned points where the backscattered light is generated can be displayed on the display device 4 for monitoring together with the display of the map of the premises or the appearance of the facility corresponding thereto.

While performing the above-mentioned monitoring, optical communication such as a telephone call or data transmission can be performed by the transmitter / receivers 11 and 12 connected to the optical fiber 5 via the multiplexers 13 and 14. The wavelength of the light used for the optical communication is made to be different from the wavelength of the pulsed light as appropriate, and for example, the wavelength of the pulsed light described above is configured to perform communication with coherent light having a wavelength of about 1.3 μm.

[0016]

As described above, the present invention has the following effects. By installing an optical fiber as a sensor connected to a transmitter / receiver of pulsed light over desired monitoring points in a premises such as a factory, not only temperature but comprehensive monitoring of equipment etc. can be performed with a simple configuration. be able to. By multiplexing and using the optical fiber as a sensor, it can be used as a line for optical communication such as a telephone call and data transmission, and installation of other lines can be omitted.

[Brief description of drawings]

FIG. 1 is a system diagram schematically showing the overall configuration of a device of the present invention.

[Explanation of symbols]

 1 Monitoring device main body 2 Transmitting / receiving device 3 Processing device 4 Display device 5 Optical fiber 6 Pit 7,8 Valve 9 Piping 10 Supporting member 11,12 Transmitting / receiving device 13,14 Multiplexing device 15,16 points

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location G02B 6/00 G08B 25/01 9377-5G // G01N 21/35 A 7370-2J

Claims (1)

[Claims] 1. An optical fiber connected to a transmission / reception device for pulsed light is installed over a monitoring target site in a premises such as a factory, and at least two points appropriately separated from the optical fiber via a multiplexing device. Monitoring equipment for factories, etc. characterized by installing a transceiver for optical communication